Engine cooling systems

Abstract

A cooling system for an engine having a cylinder block defining a plurality of cylinders and a cylinder head mounted on the cylinder block, includes a pump having an outlet which is connected, at one end of the engine to a cooling jacket of the cylinder block, the cooling jacket of the cylinder block being connected at the other end of the engine to a cooling jacket of the cylinder head and an outlet being provided from the cooling jacket of the cylinder head at said one end of the engine; the cooling jacket of the cylinder head defining a plurality of passageways extending longitudinally of the cylinder head, said passageways being arranged to conduct coolant to different parts of the head portion of each cylinder, the passageways merging intermediate of the cylinders.

I claim: 
     
       1. A cooling system for an engine including a cylinder block defining a plurality of cylinders and a cylinder head mounted on the cylinder block, said cooling system comprising a pump having an outlet which is connected, at one end of the engine, to a cooling jacket of the cylinder block, said cooling jacket of the cylinder block being connected to a cooling jacket of the cylinder head at the other end of the engine and an outlet being provided from the cooling jacket of the cylinder head at said one end of the engine, the cooling jacket of the cylinder head defining a plurality of passageways extending longitudinally of the cylinder head, said passageways being arranged to conduct coolant to different parts of the head portion of each cylinder, the passageways merging intermediate of the cylinders. 
     
     
       2. A cooling system according to claim 1 in which the passageways defined by the cooling jacket of the cylinder head conduct coolant to; the underside of the exhaust ports; the upperside of the exhaust ports; the underside of the inlet ports; and at least one side of the sparking plug boss. 
     
     
       3. A cooling system according to claim 1 in which the cooling jacket of the cylinder head includes at least one transverse passageway per cylinder, said transverse passageway interconnecting two of the longitudinally extending passageways. 
     
     
       4. A cooling system according to claim 3 in which the cross-sectional areas of the longitudinal passageways on either side of the transverse passageway are varied to induce flow of coolant along the transverse passageway. 
     
     
       5. A cooling system according to claim 1 in which the cooling jacket of the cylinder block is connected to the cooling jacket of the cylinder head via a single transfer port. 
     
     
       6. A cooling jacket according to claim 1 in which the cooling jacket of the cylinder head is additionally connected at said other end of the engine, directly to the outlet of the pump via a bypass. 
     
     
       7. A cooling system according to claim 6 in which the bypass is formed as an integral part of the cylinder block. end of the engine to an outlet at the other end of the engine. 
     
     
       8. A cooling system according to claim 6 in which the outlet from the cooling jacket of the cylinder block is connected to the bypass and then via a transfer passage to the cooling jacket of the cylinder head. 
     
     
       9. A cooling system according to claim 6 in which means is provided in the bypass to control the rates of flow of coolant through the bypass and through the cooling jacket of the cylinder block. 
     
     
       10. A cooling system according to claim 9 in which the means for controlling the rate of flow through the bypass and through the cooling jacket of the cylinder block is adjustable. 
     
     
       11. A cooling system according to claim 9 in which the means for controlling the rate of flow of coolant through the bypass is located downstream of a connection of the cooling jacket of the cylinder block to the bypass. 
     
     
       12. A cooling system according to claim 1 in which cylinder liners are located in bores in the cylinder block, the cooling jacket of the cylinder block being defined by annular chambers around the upper portions of the cylinder liners, the annular chambers being interconnected to provide a passage from the inlet at one end of the engine to an outlet at the other end of the engine.